COX-2 Expression in the Aorta of Obese Zucker Rats

Objectives: Obesity is a central risk factor for atherosclerotic cardiovascular disease. The purpose of this study was to determine whether COX-2 expression is changed in the arterial wall of experimental obese animals.Methods: COX-2 expression in the aortas of 12-week-old male Zucker obese or lean rats was investigated using immunoblot and immunohistochemical analyses.Results: COX-2 expression was detected in the tunica media of the aortas of Zucker obese rats and was prominent in the perinuclear region of smooth muscle cells in the tunica media. In immunoblot analysis, the basal (non-stimulated) levels of COX-2 expression were comparable in the aortas of Zucker obese rats and Zucker lean (control) rats. COX-2 expression in response to interleukin (IL)-1β was significantly lower in the aortas of Zucker obese rats than in those of Zucker lean rats.Conclusions: The results suggest that IL-1β-induced COX-2 expression is attenuated in arteries of obese rats, and this might be involved in the obesity-induced acceleration of atherosclerosis.